SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '771501c0cdd43c9a66f6b9e83c8be49926845939122160a41c19aa16358474f9' 
  AND token = 'WnQKPYWfd3SIu0VelLa7GpvDYqUofud3vGV/dmSdlfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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