SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '675252524febadf131bb6c09422d271ccd130365d235ebff114efba26e07aaf2' 
  AND token = 'Kld4G6MirEOwqdCVklKgx1nn46SGg95PSf43l9S3Bqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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