SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77b9a8f8e89751ff95936028cb95fa2262e02050796f67d9748bf4adf45671d4' 
  AND token = 'oHm1K5VvGrwy0ryMS4s1u5HDAijYloKacA2HIq2GLhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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