SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd05a83397f9a5f0af54de48eca8e9be364707059aaf11f4cd88f8b8c7e9ed46f' 
  AND token = '2uLv+1MxpVs2kzNNSRreb120SLUV4swpycLlgj4CLo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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