SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a03fde94637b5d38a22ccc23c2957a8d506437844f44da02d0949ff59887ece' 
  AND token = 'KwQLFYSmi3yu8T0KTx//4hktqvw/luzdPJ7CUxKD8js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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