SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '942e6ed7d5f15a994d9833e663859ff4938d25711b1e62001668a031b0284986' 
  AND token = 'cKxQxX+UhXJ6nDUOe0uJ2ZeZjfkGRA/POwKvZKhuV58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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