SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6613ba0bed90325d82232c5fa1f561ae4ba592d8b15489931bac4afbe0737d4' 
  AND token = 'I7Gmdo8SMK/JZ25L7dmRjerAP558BdhoILvQAZNvSmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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