SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '823c0b99674e1a31ca1ef802b9068fd6fefa8df26a2f4047affe45ea9fd64786' 
  AND token = 'NIf6vx0SpbfJHEQkxJEZ6W2ZGR5zH3+qOO1Uqzb1i2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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