SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb32ca90dac9112a4c47a1cfbe1386fecd0e99e13ee003ba0ce094180338ee2' 
  AND token = 'KZ7/GHcYvWTQT+H9aMwmtU6WdzWPCdcrBp2O+J5zGjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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