SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '953c3024e3a58bda2deb98cdb52fcdad1d73839208d65fe5b9a83a9c74386ca1' 
  AND token = '8pTiBUKKh3FKrbmL08bR/FHPvtRNtueMP8i2UDinGVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}