SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28bbcccfbcfa340d1e457144a9ff3899e48ee413ff1fe610ce9b8e128226428f' 
  AND token = 'wwkKpHj5PqjKDaoLbd7d17TsVIXGmWQjlEk3/UJpJ/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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