SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb2ed51ed6e9dd5dafff34ac2292de53101e2254764b02e5bbcf004aab1c8d0' 
  AND token = 'xZ8TZJz9FtT+TyWCHK8+mWo96jTQlLrTuqwGj5EQCeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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