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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f2bda90dd93b4ad1efb10a99f4367f4cedbaebb3a4d484ec30835c9e0c1dbd9' 
  AND token = 'jlbKo6FxOQGWwxTdgdWX8WewUpf6rYsvN0WsAEjaaB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}