SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3baaf81a3a7e3ee6f2ee0a9da7ffd02ea51c1c2083bf8e57f4f1d9b74025d727' 
  AND token = '7uc3nhOzhlbEGCvXt+pboDJZgEkkddLTIxKyA/Ugoms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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