SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3e59b453aaed64d8f56bcf3cf5f826b8944737594cc8e3589e9e0bc55d417b4' 
  AND token = 'TCQSUoZrdzFsY7xuEj95hLfa45oi/Kfd3JSKkc4SwsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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