SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3167924d2dd6ed35917435ac3de8931a6cda2e770a8868f8d297ca60f167f3be' 
  AND token = 'L6O2PYmc7emwnAlyMDDgJP+v4VTtibzhBOUv+mg0tGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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