SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31e524aa6c3465fdaae0852927b1a3141bd02e98b881be86d739490ebe31016a' 
  AND token = 'MF2PFT5gkblRGjvIAFeW55Xm7JNm+BP4tNt5UaIle5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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