SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f507bd5fdc4a30878e48258f299c13eec7f4968a44260544f6a6f7b609741c5' 
  AND token = '/BZcM0DAnZrwSPeYA3iO8qGTwH+G3/nmoRkNypBUf7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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