SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af27cc0d6d6eae30b6a9829e9edb202a107b161dfc3fa562804fe568d8c26c85' 
  AND token = 'KhsEMeTapa2fDVZnOEyLFBtYBiR0A1KIg7MxGrBKHlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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