SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0bc3a3a565034799a767809b360f5d3a2e66537752df1f8290aed1bd91822df' 
  AND token = 'vIiUL3qNHiPaXYhS91APxDOKw6c+rtVjRxK9OAg6mvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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