SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf34089abb6e38aac85b50ca2c4146c879490f9d544fd3d742f44029233b6fa7' 
  AND token = 'Vm7oZBzwI6y+CdzdjpFiNTYnLcqI46qNGoJLfz4dgNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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