SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53a1faf043795721d2089705f2e701878b60b99bae2eeafe386e6f45149f12d6' 
  AND token = 'AlC4XZybFgYQJGg6WljL5e4oIwrO26/WfYFGkivEAx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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