SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7e23f2ada02f6d643a1d5407d5b817551734bd86aca2f767c743ef8d36b5db2' 
  AND token = 'htomsX8WYZ//fm3j1Y9zEzdfO/8XC4aK23Ed3hVnkcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}