SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f66f4ed9ca338db651828109c17405ae466901e8259783436940c5f16b832ec' 
  AND token = 'cXoyZk5il0VAYHk93/4Oe1lliVsRIpuye94RsJdvXlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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