SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcca8d8ea144cb24af338a08f0293bd7c1e8608253b17b7d71009fdcd2792254' 
  AND token = 'QAipOVHE5LahKiKOuH2721YbPsJhW3Uixj65m/+kq+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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