SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '920908259bf293c8c61ec38efb888012647eaba3d7a55b82655c630451e47759' 
  AND token = 'D6Aofyq+PdVrzpfs+NUV/a+3TZWfqORYOds3WNXxVCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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