SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '276cbf8043067a094a79a57b517d4111ceff1c0e2bc9282909b5db58eac5a3d6' 
  AND token = 'va6XofyqEczjaHZ6DuXXaG7ovec/KJ4UKsWidJExvvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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