SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384a51a593a5d879179b79852b9796642793af009de6cb842a230fcb17525931' 
  AND token = 'aAkrM0NOqYIzv95CvCivrY4y4/VRkoUCNXBD7vWWIVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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