SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cc7f83b60fc1bdbedfba297922763e21fa49871c33273a4792be29b5a506a91' 
  AND token = 'ZSCHjpS4/bKF6inhFzFUFsd4ZaBTuXX/ZpXNLPD591I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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