SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bbb6de167dd49a6816164eb0a9c6b9c54101099fa8257b04ebfef650194b1f0' 
  AND token = 'a3aAMuIB7oqkz5x0GInRz/X91f6PD4kWATukv69ltrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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