SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e5a921c8eeb3f7af27b1670195db00fd719e867474b680b85cf30fa2f77eebe' 
  AND token = '/E+rxswJizQAs6zqlgYGZAwRcWrVQ6HoTikPqyDAI24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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