SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '602ccf0ac48f345a630a6389fdb061ad45f4836094a0aab1034112ee69052d66' 
  AND token = 't9h2E9exLrb98rVkc+si/Yime594GtFu7leGH4CJjxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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