SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f93836fd763efcbc0a779d6d5093eda577f53f94c1dcd29fe61cd0136a2576f' 
  AND token = 'h0+kOIaNBg3gx1Xq4q1n8KPbzHbGY6LuCK7McCsdjjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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