SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa4fe08262693fed87da77d1e61c6366276d45013050585df46300437c0fcfb2' 
  AND token = 'Gg0OKjYR0txY2821pK/s2nkIbX9M7BUJXfN0tkSFcwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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