SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2633ed40a75926e321312b78d287453ddd5dfe14696fbb0e339fdfd767ee4220' 
  AND token = '/2CAZqDuvkgh2k1jeGsYCk8TsBmaDZ/s6qvqKjysBw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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