SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a15222f0bde67f6fd72617fc125b5226342900dae2b5f4b94715bc850660476e' 
  AND token = 'oGxFnfgYySBl7Bd3IDaRrUbcFF3SkU55qqF9PrsdJvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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