SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcd757328d5bf285870a812c4fb347ab8003db6640baba6be9d466e691769161' 
  AND token = 'm5JvdXb4aNl3QBUy0KT0RgqH93BbA0ItaabCVX2rSmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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