SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58513d1089d95613fb40029ba0b3ebb937d3e421e7f208b49ec377fef457c765' 
  AND token = 'iOVshwhfBKkg6163stHHDe8sMqkAyws5k2tEFkgWw9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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