SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '440db5d95f569eca7f5e431afb6f112ecd970712d5ab5c93d5777ffe88fad45c' 
  AND token = 'V7zYn50TYXTaRzrQPMXl0dyBhvMsFdklitiPwAyydB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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