SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68f2bca95d49e5dc266fb51045ffa0066eae549573c15549c9412fc38863f182' 
  AND token = 'ecyePjUGnIGOBIGEdkyYVA2QNelNc0l9pkCss7pxBQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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