SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '833659df0563e2aa1a371e4d7b86095501eb739a266f423c4e333e319729abd9' 
  AND token = 'Tef+UvJ6PfZBXawkmPdyXrLqKpzT+WzijW21fxFqOBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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