Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75a706304892769092552745a6e8711b418cf938ef9ba145960d7520116b3a40' 
  AND token = '1j9naInvLY9jbztxP1LreEJOxGlS0W2bFCxtBRpYHy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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