SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db7c85afd85a66316d585082724777d674b6cbcbb6624f57cb17b9778d0803e' 
  AND token = 'eiyaJvdLBgKB40DilOduivrK4B7DAXhXZJo3keFUlI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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