SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daa9d93d6d0bd65aca06c4ed47807f5ccebaf4befcc51ca0178161d111380594' 
  AND token = 'oJrWBjvfcvL1XE7SqKktmmKQXrMHYkobLUpcb4yb+g0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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