SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ff89a59ad2da26adc43e38963c17113e0acf23f1f45421c1777705e5a5a82a1' 
  AND token = 'r+CMKFj/TT0phRR9b8+DCAF1grqhX3XUKxKTLgLN3Yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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