SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1da79eeee9a48a99695e575f3a35232838bac323242ed81e23fa99b67710f705' 
  AND token = 'k9SM7dZc7UVJqwORc++CUr/hb/+3AyP8KqKoQsG6Vjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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