SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '140ab7a86213b3c46d423b0df0c417ad2c1ab994b6551ff9388e082041070f2c' 
  AND token = 'nqLzd1k9v+5o7f5XPZeqtlIOYJEDxXxWESGPzRIMg28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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