SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db1028f05a66ab2694fcaf80955f78a3a8767765a3e3e99c56ec57c21cde8dd7' 
  AND token = 'BVXWpQvdSnhPP1FDcbjOF6daebAPjfjL+UE1w6etJf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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