SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc7afacd4abe794d4a83900d91ca94e3b0584cf1bf80fd880285900db70631c0' 
  AND token = 'LQiwQEMIoVwwsXdNkxxGpYXSfE1z6chcQqxuTo1fZvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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