SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f2f201c964ce30cd14cc8e9b02e0bb0bdbf6daa8e41ef01dcd491779c75cff1' 
  AND token = 'XpNwpmFd35gChm94EtbYTBNkpF4/1uRHBZAm0s3x2JM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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