SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b92904050f366bbd939837073ceda8edf95647def06783a0035269424921810b' 
  AND token = 'wBjlkDY9yY1tt5YbVsKjC+rqD/70Ic3TZDg/I2kTTXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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