SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '594a9cb5b955d83d7467ff2e3173fc6563a5f89ea06a9c3babc4db610763e583' 
  AND token = 'LXmNqUl3wKDuMuR7DRPvn/SKeVTuxWESKhXvCkgQV/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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