SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1174081db2ee6d5a4fd3dca892d4394ee0b4ee39b322f0c593eb4a0741169ab8' 
  AND token = 'E9AUczJJjmYH1V2P/CSTAYMSzGe5pSk6FeaBNxvD0AY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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