SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97754fbbddab1a9fc0aa942b7c40312aea295e819027d5da3dc5037608df6ab1' 
  AND token = 'StvQxkIkKbz6yeLXaE+qg4gB6to78GijTftT9dv3EXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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