SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b895fe1710aea208a9e0d28fbbb0154cabfb51be0bb51448e3583ea36d985c08' 
  AND token = 'iGkdmP9J2cJFhu5CZycXvdSOVTCkmp0NnNah96aSyRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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