SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91910aca42c467cb87b4da7549cd0fd6d7eacda3c44726b41d96a80c29ad08aa' 
  AND token = 'z7WiPtS4IR/HjtO3wJtEfa6STzgeXxb3ciPMvrxAjEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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