SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f42a17117b3af8c9720969161f9379022d330ff0b8adfd297c0ef0640753c3a2' 
  AND token = 'ztnmmddtPNHPBfmI6sIcEJQoJQo2DoN3e5coEXTBqPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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