SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9de79963c6fa340ba13bdb40f65eb23e99a85872b95f8cd76f47e9fef51333b0' 
  AND token = 'Cb4Sv4KN6fZQszGEi1nW0TVZ0R5N+ND2sXYWR+8bXNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}