SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab293a97960bfdfd5ccd6b44c9bbdf7a753ab88138356896a2ba5da61a5cf28f' 
  AND token = 'YuTI8HjQ/esGybKgUIwMgm87VJkb1fmye2HDi0U5N60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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