SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c6c3a643912268cc61d068e150020ef8a30b910c8c2e532bab3d572c82f898' 
  AND token = '4xsAMcCtZXg9o4y/EEZrEZ9TS7f6lyDTKrhrIVS6ijI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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