SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46b4a947608d7b1f630ca199ee961c09358cf3d0ca5963e8b034f7d9a0da267d' 
  AND token = 'uVjhQ1rnSWrLJAfM/pP2kKbMwzx4cRCsKUB64lBqarU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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