SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83c4f408504c92cc0462b41a4e32e53eb2055cb08f6093bd0fe80fef224da8ef' 
  AND token = 'TLsrWoRivSeCqKd9Iwz7YOV92KAGkGMagbdEVsmf9Cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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