SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3b26a1c1d930314ce72499c4f294bf8682c5a5e217d1ff232b0470e025f13fd' 
  AND token = 'VxaLTbmdGkR2P439EzzEYt32ijLo9duLHBqVmbUiSGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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