SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bec3823373fec486b8dad0d149b3374b2b8678e4950168ba09bec60cc8c4155' 
  AND token = 'G4BS1VBAPzruO4BqM24SZZ+so7nrPPxOq7zWfXKSU/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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