SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef362d633e851edcc78305fecb46c6772b7911f6c344f66b445318a83a5c8af4' 
  AND token = 'DLBD/JDCgT/oTlCkxV3pJb03jEXQ9/ANSHEGP8TzOTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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