SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '744eb65008284e2aafee9d2405ea473493b082b5c1571db4df563144c1115bb1' 
  AND token = 'XGjUofgLsHdiAVyaXAUVJ6Kcs+GEzO3uTcrFhjsGlwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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