SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bc96a5d9bd899ac12e13dae11dd4f90f8fb1524a12d2a192f38047d3281b129' 
  AND token = 'qsRuFK+zGYy8aHnkKUYMk7DpMplU+KkSBocbZW5gXiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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