SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a0d89bb4ede238e6428db3521b30d80e5c5ebc2108f5c5e1bcb6c33efbfb1de' 
  AND token = 'qA997FIGtxyo0F8ZvQcbjlLb6FXS1YDIqHfVi15FZ4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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