SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '073835e3292ec008be4203bf582da4d9e8c5a91ff3ea29e366d4fd8fefa61282' 
  AND token = 'o/mXsZ+dc49+LSGq0xeJhMz+FUxczA6xaqgEWG0GPFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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