SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c86049d76e53563ded3adb7db2d62f50a71ea936e67660196f32313a83dfc98' 
  AND token = 'r+PSbXsQB0ZrYWjyGKPRl/pZFvr84qRI5s5usdS/JGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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