SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c938aced68799a799dd9165440ba59f47033d440e7f0b6424e4445e5a24c8a' 
  AND token = 'RidLQ2KtuAV/Wv5Jwn0sF8LwiKuofxPnQeMwnyW8vH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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