SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c11dd26a808e08001dbcce4a0789437cf9a3a631b1be3654426c7e30fdc37157' 
  AND token = '3DTEsq5HAWuPik7DwAWSziYa/Z+UhQmOrGJFYjogO9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00122

JSON explain

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