SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c0e7e628f355e16c86764f1ed86449f3625b629ca6f6c3108522f8d922575a9' 
  AND token = 'FCYQ2O/lUJjfscq6eVfQcCPujL/FqaGy6JznTGG1Wg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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