SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88104dc9f4b4e48d21db3782c5dcf398b409a8cb228986dce29a3c0e520ce038' 
  AND token = 'OQTCm+oThi1Gqkcs5pXlRCL2TR98fntAUj9IQuKWrsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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