SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31f30eac9674b82ca861ac42e453f1445662db6fabf91fab21b85155bef8f0ca' 
  AND token = 'fQCFEuIV9IB9nlELnbuSlpR8XcLyakYbAebuAo27RZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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