SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd10432cf129e84bfb780120a4cff7c538343e35c1d8ccb4637901dc3c5fbda54' 
  AND token = 'j572OIvqk9lftq6blFZ7UxziiF881colZNwfXFdx3Zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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