SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9d99402869bb53b668199fd8b7cfe9b52eaefb406c4e0cd320ac00d9de9ed3d' 
  AND token = '0VEixaer16saBgnsiOHeVfMPxOx58MlE5elsRUa2byI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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