SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c197a74d492fe22b1cb5b3314198d55eff25fbd71cee83f2267dd9394bea4cd' 
  AND token = 'UR1QDFGwSQAZjhRR/JWXoHWxwvBffPOAlvBTAxgFH9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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