SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcf36bd5b9bbad123ca0a00a8dbc8fde58d1c40297cd865bbd2fd15cebfb379c' 
  AND token = 'izwbdTGwYEKQNpvl29iCcobOH8cQYWxBESZV7z6i+KM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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