SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99dd35deb4cea186e0bdb0883a30cd501c493027226a9b5ca6ced04ecb0d7593' 
  AND token = '+YR4D11OC5ChAHhBNSdZblwEpN1w3Q+mQwXd1umW08w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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