SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1be34b226db8d7352f4b04284586f2dda73208c0d91e8b75013dde3930e2f433' 
  AND token = 'EjXpzUyd2KCVkHBXGqzzxmoPTM7ZSpVOtoqhqsH/uoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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