SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e143bbb19b1519c408f8939c46921d3d1cc622ccf519f39cfba0203712ceb40a' 
  AND token = 'vKSuVgN7gQOg+fqJ3XFYXU4tgD5+q9NCGjIe3/15zH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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