SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7141fe70fd87986133928505f97a02689c638bf51dcf1dee36135382ee422616' 
  AND token = 'x+g5mkSGpA+S3IDt7bK5jYjHOgqJtPS6mJmNIYB7Bn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}