SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35a3517a9df44dd2650d6c1e4e1c37bcd283892d389ecced4978113d31ce97f5' 
  AND token = 'FAYGGMM8Z9CXpmJ1EB55KuE9OjdkjyId2dRNPvrRES4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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