SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cf5ce6db68de18db4b95269cbd217883f2160f039075949b8cb2cb70f58abc7f' 
  AND token = 'L+cuycWshWHecvrFmvUkNwXmGkSDS+5Vbtt95avI8OQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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