SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ad43f9adafb747d2c6489a4b0d2ce01c1c65e47cbc9acde93c478e302f33fc1' 
  AND token = 'NRGlEsBsteHaoAh0BNAkVcOxa76NmgjC2lRqHk4MjMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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